CVE-2026-74624

In the Linux kernel, the netfilter nf_conntrack module can emit logs for malformed TCP or SCTP packets while it still holds the conntrack lock. When nfnetlink_log and conntrack export are enabled, the logging routine can re‑enter the conntrack core and attempt to dump the same entry again. Because both paths try to acquire the same lock, this recursive re‑entry can deadlock the kernel network stack, halting packet transmission and leading to a denial of service.

All Linux kernel releases that include nf_conntrack and nfnetlink_log may be affected. No specific version list is provided, so any kernel with the nf_conntrack module is potentially vulnerable until the vendor releases a patch.

The flaw can be triggered by sending crafted TCP or SCTP packets that cause an invalid state. With an EPSS score of <1% and not listed in the CISA KEV catalog, the likelihood of exploitation is low, but the lack of widespread public reports does not diminish the theoretical risk. Based on the description, it is inferred that the attack requires network access and the ability to generate malformed traffic, which can be achieved by a remote or local adversary. Because the vulnerability can freeze the kernel’s networking layer, the impact is severe but the exploit vector is limited to entities that can send those packets. The CVSS score of 7.5 indicates a high likelihood of denial of service, and the low EPSS suggests a moderate overall risk, warranting immediate attention.